GEOLOGICAL CLASSIFICATION OF SOILS 57 



Volusia series of the highlands, is low in lime; while 

 the same soil just south of Lake Ontario, obtaining its 

 wash from a limestone till (Ontario series), is rich in 

 lime. As may be inferred from the above comparison, 

 the glacial lake soils of the United States are variable 

 in their fertility. 



The distribution of the glacial lake deposits, as seen 

 from the soil map of the United States, is fairly wide. 

 Such soils are found in areas large enough to be of great 

 agricultural influence, extending from New England 

 westward along the Great Lakes until their greatest 

 expanse is reached in the Red River Valley. These de- 

 posits make up some of the most important soils of the 

 northern states. They are valuable not only for ex- 

 tensive cropping with grain and hay, but also for fruit 

 and trucking crops. The Ice Age was certainly not 

 in vain as far as the production of fertile soils is con- 

 cerned. 



44. Lacustrine soils — recent lake. — There is yet 

 another lacustrine soil to be considered besides the one 

 just discussed — recent lake soil. While the glacial lake 

 deposits were formed many thousands of years ago, the 

 lake soils of the second group are in process of construc- 

 tion. It is a well-known fact in physical geography 

 that lakes are only enlarged stream beds, and are doomed 

 ultimately to be filled by river sediments. Such soils 

 have been reclaimed to a certain extent, but their acreage 

 is not large enough to give them the importance of 

 the glacial lake soils. The lake soil is usually of a fine 

 character, rich in humus, of good tilth. If properly 

 drained, it is almost invariably highly productive, and 

 is adapted to a variety of crops depending on climatic 

 conditions. 



